Hmm, this is most strange.
The server had malfunctioned for some days when I wrote my question. Being away for some days, and today I picked the server out of the closet to do some investigations as suggested above. Power on - and everything works....
So I seem to have a self healing server, which in one way is very nice, but I hate to have these situations when I cannot find the cause of the fault. Most likely it'll come back again.
Thanks for you good suggestions, I'll save then until it's needed again. ;-)
I could post similar thread but with 7.10 version.... Sometimes it just goes mad and settles down after few days....
I've seen some strange warnings about sql transactions taking too much time, but I guess my database is also messy after all these years of daily usage.
I've regenerated media database and things seem to be a bit better than before (my living room MD crashed DCERouter when I went into Audio or Video entries on UI2, so I guess this was in relation with media database being messed) ...